1# Generate SYS_* macros from a list in a text file.
2# Copyright (C) 2017-2021 Free Software Foundation, Inc.
3# This file is part of the GNU C Library.
4#
5# The GNU C Library is free software; you can redistribute it and/or
6# modify it under the terms of the GNU Lesser General Public
7# License as published by the Free Software Foundation; either
8# version 2.1 of the License, or (at your option) any later version.
9#
10# The GNU C Library is distributed in the hope that it will be useful,
11# but WITHOUT ANY WARRANTY; without even the implied warranty of
12# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13# Lesser General Public License for more details.
14#
15# You should have received a copy of the GNU Lesser General Public
16# License along with the GNU C Library; if not, see
17# <https://www.gnu.org/licenses/>.
18
19# Emit a conditional definition for SYS_NAME.
20function emit(name) {
21    print "#ifdef __NR_" name;
22    print "# define SYS_" name " __NR_" name;
23    print "#endif";
24    print "";
25}
26
27# Bail out with an error.
28function fatal(message) {
29    print FILENAME ":" FNR ": " message > "/dev/stderr";
30    exit 1;
31}
32
33BEGIN {
34    name = "";
35    kernel = "";
36}
37
38# Skip empty lines and comments.
39/^\s*(|#.*)$/ {
40    next;
41}
42
43# Kernel version.  Used for documentation purposes only.
44/^kernel [0-9.]+$/ {
45    if (kernel != "") {
46        fatal("duplicate kernel directive");
47    }
48    kernel = $2;
49    print "/* Generated at libc build time from syscall list.  */";
50    print "/* The system call list corresponds to kernel " kernel ".  */";
51    print "";
52    print "#ifndef _SYSCALL_H"
53    print "# error \"Never use <bits/syscall.h> directly; include <sys/syscall.h> instead.\"";
54    print "#endif";
55    print "";
56    split($2, kernel_version, ".");
57    kernel_major = kernel_version[1];
58    kernel_minor = kernel_version[2];
59    kernel_version_code = kernel_major * 65536 + kernel_minor * 256;
60    print "#define __GLIBC_LINUX_VERSION_CODE " kernel_version_code;
61    print "";
62    next;
63}
64
65# If there is just one word, it is a system call.
66/^[a-zA-Z_][a-zA-Z0-9_]+$/ {
67    if (kernel == "") {
68        fatal("expected kernel directive before this line");
69    }
70    if ($1 <= name) {
71        fatal("name " name " violates ordering");
72    }
73    emit($1);
74    name = $1;
75    next;
76}
77
78# The rest has to be syntax errors.
79// {
80    fatal("unrecognized syntax");
81}
82